SEATTLE--Clean energy innovations may be getting off the ground in labs and start-up business plans, but making them commonplace for consumers is another matter.

"We're not getting there very quickly because no one's paying the bill," said Stan Bull, director of research and development at the National Renewable Energy Laboratory, which is exploring alternative fuels such as ethanol from corn stalks, waste paper and wood from forests thinned to prevent wildfires.

The government must do more to speed up the spread of greener technologies, agreed Bull and other experts at Discover Brilliant, a conference exploring sustainability in the business world. Tax breaks and other incentives in Japan, Germany and Denmark have helped to accelerate the development of solar and wind power there, for example, as the United States has lost ground over the last decade and continues to rely upon fossil fuels.

"The bigger problem isn't an energy problem, it's a carbon problem," said Steve Selkowitz, building technologies program leader at the Lawrence Berkeley National Laboratory. Yet, new laws and tax breaks are only part of the picture. And inventing new gadgets won't achieve progress if Americans continue to waste so much energy. "What we can learn from developing countries are smarter lifestyles," he said.

For instance, heating, cooling and lighting buildings accounts for nearly 40 percent of the nation's carbon dioxide emissions, an amount poised to grow faster than in any other sector. Designing new homes and offices as well as retrofitting old ones to shrink energy demands by 90 percent would help, but merely halving energy use indoors would not do the trick, he said.

Individuals and communities are likely to play a larger role in determining the future of energy, according to both Selkowitz and Bull. No matter what mix of wind, solar, or geothermal power takes hold over the long term, Bull foresees a hybrid between centralized sources and decentralized generation in local communities.